Engine fuel system



Jan. l, 1952 J. N. NovAK ENGINE FUEL SYSTEM Filed4 Nov. 13, 1945 .1f .ai f/ 5737@ ff Fatented jan. 1, 1952 Joch, o.- l

ENGINE AFUEL SYSTEM JosephN. Novak,` Cleveland, Ohio, assignor to General Motors Corporation, Detroit, Mich., a

corporationof Delaware Application November 13, 1945, Serial No. 627,988 11 claims.l (criss-36.41

Thisinvention generally relates to internal.

combustion engines and more particularly to fuel injection systems therefor. V,

The principal object of this invention is to provide a fuel system including means for separating impurities from the fuel while priming the system to insure complete lling of the system with fuel free of impurities and for evacuating the impurities and vapor therefrom before starting of the engine and during operation thereof to insure prompt starting and efficient engine operation.

The fuel system including novel means by which this object is accomplished and other features thereof will become apparent by referenceto the following detailed description and single schematic drawing illustrating one form of the invention.

The fuel system includes a plurality of engine operated fuel injectors I adapted to be supplied with an excess of liquid fuel under pressure for combustion in order to also permit cooling and scavenging the injectors by an engine driven fuel transfer pump 3 from a fuel tank 5 through a separator 1, a strainer 9, a filter II and connecting supply pipes I3, I5, I1, I9 and 2|, respectively. A non-return spring seated check valve I4 is included in the tank outlet pipe I3, and a by-pass pipe 23 including a check valve 25 is connected between the inlet and outlet pipes I1 and I9 of ythe transfer pump 3. The check valve 25 is seated by a spring and the outlet pressure of the transfer pump 3`. The excess fuel supplied to the injectors is returned to the fuel tank 5 by means cf injector outlet branch pipes and a return pipe 21 including a spring seated check valve 29 which'` is opened by the pressure of the fuel returned.

The separator includes a header 3| and a detachable bowl 33. The header is provided with two manually operable valvesv and 31 and a manually operable plunger pump 39 is threaded thereto.

The valve 35 serves as a by-pass and separating valve and is shown in the separating position to establish a connection between passages 4I and 43 in the header 3| and to also establish another connection between passages 45 and 41m the header passage 41 and pipel I5.so that the separator is by-passed.A

The valve 31 serves as a priming and evacuaty ing valve and is shown in the priming position A-pump discharge passage 51 leads from the pump cated between the injectors I and the-check valve i header. The header' passage 43 `is of greater diameter than the other passages and a large diameter separator pipe 49 extends downwardly therefrom to a point adjacent the bottom of the bowlv33. The tank outlet pipe I3 is connected to the header passage 4| and the pipe I5 is connected between the header passage 41 and the inlet of the strainer 9. The header passage opens into the top of the bowl 33. Movement of thevalve 35 at right angles from the separating position,4V as shown, to the by-pass position ,con-

nects -the pipe I3 and header passage 4I to the passage 54 and includes a spring seatedcheck valve 59 which serves as a pump discharge valve. A priming pipe 69 is connected between the header passage 5I and the return pipe 21 at a point lo- 29. A discharge pipe 5 I isconnected to the pump discharge passage 51. Movement of the valve 31 clockwise at right angles from the priming position as shown, .to the evacuating position connects the header passage 53 to another header passage 63 from which v,a separator evacuating pipe 65 extends downwardly to the bottom of the separator bowl 33. The bowl is provided with gauge glass 31 connected between the upper and lower vextremities of the `separator bowl 33 and a drain ,Y

plug 69 is provided in the bottom thereof.

Priming of the above described fuel system to l insure evacuation of vapor and complete filling of the system with fuel, from which dirt and water is separated, is Areadily accomplished by placing the valves 35 and 31 in the separating and priming positions, respectively, as shown, and

operating the plunger of the priming and evacu.

ating pump 3,9 manually. This causes vacuum to be applied to the injector fuel return pipe 21 through theV connected priming pipe 60 which causes the check valve 29 to be held in the seated positionrand-through header passage 5I, priming valve 31, header passage 53, pump inlet check valve 55, pump passages 54 and 51 and discharge of vapor through the pump discharge check Valve 59 in the pump passage 51 and discharge pipe 6I of the pump 39 connected thereto to cause ilow by-pass and separating valve 35, enlarged header passage 43 and separator pipe 49 to the bottom of large diameter separator pipe 49 and bowl 33 causes separation and settling of impurities such as water and sediment from the fuel to the bottom of the separator bowl 33. Complete filling of the remainder of the fuel system with fuelv lter I, pipe 2 I, injectors return pipe 21, prm- 4 3 ing pipe 60, header and pump passages 31, 53, 54, 51 and check valves 55 and 59 and the pump discharge pipe 6I. Discharge of a quantity of fuel through the; pump dischargetpipe insures,l complete filling of the^system with fuel -anclithereby insures prompt starting and efficient operation of the injectors I and engine. 'I'he impuri pumpzpassagesf63,1.53, 54 andVv 57 gandfdischargefv pipe 6| through which the impurities.;areevacu-l ated, by: further manual reciprocationof.; the plunger. of thepump 39.l The valve. 35. is left in; the separation position and valve 3.1 is.mo.ved.. to. theA evacuating positionwhen the. engine;;is. started and operated to cause continuousgseparation and settling ofimpurities from thefuelin the manner described above and toprevent return fuelV from being forced by the Atransfenpump 3 through the above describedprimingand discharge pipes and passages and to cause` return of fuel directly to the tank-throughthe return pipe 21 andchecklvalve 29'..

It will beevident that the impuritiesmay be evacuated fromthe separatorbowl 33sinthe mainner described` when theengine isoperating asthe suction developedl by the manually operated` plunger p-ump 39' is applied to the bottomseparator; bowl 33. whilethe transfer pump 3 applies suction to the top of the bowl.

If desired the separator maybe by-passed by movement Vof the valve 35 to the by-pass positionto remove and replace-parteci the separator while the engine is operating.4

I claim:

1. A fuel system including a fuel tank, afuel injector having a fuel supply connection connected to the fue1 tank and including afuel pump and a separator tank, said separator tank having a fuel inlet passage extending downwardly from the upper portion to the lower portion, and a' fuel outlet passage in the upper portion to sepa-rate impurities from the fuel and evacuatingpump means having a suction connection communicat ing. with .the lower portion of the separator tank and a discharge passage for evacuating separatedr impurities from the separator tank and for drawingrfuel therein.

2. In a fuel system for 'an.engine,. a fuel tank, an engine fuel injector having fuel supplyA andy return connections communicating with the: fuell tank, said fuel supply connection includingV afueltransfer pump and aseparator-tank having a gauge glass communicating withv the upper and lower portions, a fuel .inlet openingfinthe upper. portion communicating with the fuel tank and'a fuel inlet conduit leading downwardly-therefrom to the lower portion of the separator tank anda fuel outlet opening in the uppery portion of the separator tank communicating with theinletof the fuel pump and evacuating pump means having suction and discharge passages, forevacuat-` ing the separated impurities from the-separator` tank while the fuel transfer pump: is operating, said suction passage of the evacuating pum-p communicating with the lower portion'oftheA separator tank for drawing separated impuritiesfrom` thev lower. portion ofthe separator-tank andi 4 thereby applying suction to the fuel inlet conduit connected to the fuel inlet opening of the Separator tank for drawing fuel therein.

3.1In a-fuel system for,an.engine;-,a fuel tank, a: fuel injector'having aefuel supply A'connection and a fuel return connection to said tank, fuel supply means in said supply connection including a.-.fuel.transfer pump and a separator for separating impurities passing therethrough to said injector, an evacuating pump for said separator, acheck valve in said return connection for allowing'onlyJone-way': flow of fuel from said injector to..saidtank.and.atwo way valve connected to said return connection, said separator and said evacuating-pump said two way valve being movable to one position to connect said evacuating pumpA to saidreturn connectionfor. evacuating vapor .from saidinjector ,and said .connectionsinA order to completely fill, saidinjector and-,said connections, with .fuel free froml impurities, said two way valve beingV also movable to a second.

position for connecting said evacuating pump tosaid separator for evacuating the .separated .im--

purities therefrom.

4..,In a fuel injection system for an engine, a. fuel tank, a fuel injector, a fuel transfer pumpand a two way valve connected in series between.

said tank and said injector and a separator hav.-7

ing inlet and outlet` connections. connected: to said two` way valve, said two4 way; valvebeing movable-to one positionfor connectingsaid'sepafrator inseries with said transfer pump -to separate-impurities fromthe fuel.r supplied to said injector by said pump, said two way valve being; alsol movable to a second positionfor connecting said transfer pump directly to said tank andan evacuating; pump having a suction connection communicating with the lower portion ofthe separator and animpurity dischargeopeningy and operable to evacuate., impurities fromthe separator and to drawA fuel therein when said separator is connected. in series f with. the transfer4 pump.

5. Afuel injection system for..an engine, afuel tank., a. fuelinjector, aifuelltransferpump and.

' a two vwayvalve connected in series between said tank and said .injectoixi'or supplying fuel to` said. injector, a.separator liaving inletand outlet iconnections connectedtoV said'two way valve,psaid valve .being movable .to one. position for connectingsaid pump directlyto said ,tankfor supplying fuelito said injector directly from' said 'tank,.said. valve also being. mo.vablev to a second position for connectinggsaid separator andsa-id 'pumpin series' relation between said tank" andsaid .injector for supplying. fuel free from impurities to said'in- .lector fromsaidftank, a fuel'return connection including a check valve connecting said injectorA to said pump, saidv check valve allowinggonly oneway iiow. of fuelfrom said.' injector to said tank.v an evacuatingjpump; anda secondtwoway valve connected" to; said fuel return connection; said; separatorand saidevacuating pump; saidrsecond twoway valve-being movable tooneposition for 1 connecting'said 'evacuatingpumpto-` said fuel return 1ine"for-evacuatingjvaporfrom-said separatorl said transferpump, said injector and said'.' return `connectiony in order-to"completely fill -'said" injector-withfuel free from impurities; said seca ond-twol way vaI-ve'alsobeing ,movable-to a'second position-for connecting-gsaid'fevacuating pump-dii rectly to-said frepa'ratorffor evacuating the-sepa'- rated impurities therefrom;

6i In a fuel injector lforan engine; a' fuel tank," a fuel injector, a) fuel supply connectionandr'a fuel-returnconnection: fromsaid tank to' saidinjector, said fuel supply connection including a check valve adjacent said tank allowing only one-Way ow of fuel therefrom to said injector, a two way valve and a fuel transfer pump, a fuel by-pass connection connected between the inlet y and outlet of said transfer pump and including a check valve allowing only one-way ow of fuel from the inlet directly to the outlet side of said transfer pump, a separator having fuel inlet and outlet connections connected to said two way valve which is movable to one position for connecting said transfer pump directly to said tank and which is also movable to another position to connect said separator in series relation with said transfer pump for supplying said injector with fuel free from impurities, said fuel return connection including a check valve adjacent said tank for allowing only one-way flow of fuel from said injector to said tank, an 'evacuating pump and a second two way valve connected to said fuel return line, said separator and said evacuating pump, said second two way valve being movable to one position for connecting said evacuating pump directly to said fuel return line for evacuating vapor from and completely filling said injector and said connections with fuel from said tank, said second two way valve also being movable to a second position for connecting said evacuating pump directly to said separator for evacuating the separated impurities therefrom.

7. In a fuel system for an engine, a fuel tank, a fuel injector having a fuel supply connection and a fuel return connection to said tank, fuel supply means in said supply connection including a fuel transfer pump and a separator for separating impurities passing therethrough to said injector, an evacuating pump for said separator, a valve in said return connection from said injector to said tank and a two way valve connected to said return connection, said separator and said evacuating pump, said two way valve being movable to one position to connect said evacuating pump to said return connection for evacuating vapor from said injector and said connections in order to completely fill said injector and said connections with fuel free from impurities, said two way valve being also movable to a second position for connecting said evacuating pump to said separator for evacuating the separated impurities therefrom.

8. In a liquid Vfuel supply system for a dieseltype engine having a manifold, a fuel reservoir, a fuel-water separator tank, a conduit connection from said reservoir to said tank, a conduit between said tank and said manifold communieating with the upper portion of said tank, a water outlet conduit communicating with the lower portion of said tank, a fuel overflow conduit communicating with said manifold. pump means having an inlet and an outlet, and valve means for connecting the inlet of said pump means alternatively with said water outlet conduit to discharge watei from said tank or with said overflow conduit to prime said manifold of said engine.

9. In combination, a tank having an inlet and having an outlet near the top thereof, a sight gage attached to said tank for indicating liquid levels inl said tank, a manually operable cylinder and piston pump mounted on said tank, pump supply and outlet passageways in a wall of said tank and communicating with said pump, two check valves in said passageways, a rst of said check valves in said supply passageway permitting flow toward said pump only, a second of said check valves in said outlet passageway permitting ow away from said pump only, two pump inlet passageways in a wall of said tank connected with said supply passageway and communicating with the inlet side of said first check valve, one only of said inlet passageways communicating with the lower portion of said tank, the other of said inlet passageways communicating with said outlet of said tank, and valve means for selecting one or the other of said pump inlets.

10. In a device for separating desirable and undesirable liquids of different specific gravity in combination with a continuous conduit system having a zone where said desirable liquid is used, a separating tank in said system upstream from said zone, an inlet for mixed liquids to said tank, an outlet to said system from that portion of said tank containing said desirable liquid, means for moving said desirable liquid through said system, a pump having an outlet and also having two inlet passageways, valve means for selecting either of said pump inlet passageways, one of said inlet passageways having a conduit connection communicating with that portion of said tank containing said undesirable liquid, and the other of said inlet passageways having a conduit connection communicating with said system downstream from said zone whereby said pump may discharge said undesirable liquid from said tank when said one inlet passageway is selected, or may pull desirable liquid through said tank into said system when said other inlet passageway is selected.

l1. In combination, a tank having an inlet and having a first outlet near the top thereof, a second outlet for said tank communicating with the same near the bottom thereof, a pump mounted on said tank, said pump having an outlet, said pump having an inlet, and valve and conduit means for connecting said inlet of said pump alternatively with said first and second tank outlets.

JOSEPH N. NOVAK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 851,953 Macrate et al. Apr. 30, 1907 1,062,236 Hitchcock May 2,0, 1913 1,650,478 Wimberly Nov. 22, 1927 1,736,033 Barlow Nov. 19, 1929 1,776,498 Freeland Sept. 23, 1930 2,024,133 Harding Dec. 10, 1935 2,062,644 Ensign Dec. 1, 1936 2,118,079 Goode et al. May 24, 1938 2,157,737 Janssen May 9, 1939 2,183,616 Korte Dec. 19, 1939 2,201,019 Zotter May 14, 1940 2,215,680 Wiley et al. Sept. 24, 1940 2,308,656 Harth Jan. 19, 1943 2,322,131 Heftler June 15, 1943 2,401,880 Parker June 11, 1946 

